﻿<!DOCTYPE html>

<html>

<head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
    <title>12_点光源</title>

    <script type="text/javascript" src="../js/Oak3D_v_0_5.js"></script>

    <script id="shader-fs" type="x-shader/x-fragment">

        precision mediump float;


        varying vec2 vTextureCoord;
        varying vec3 vLightWeighting;

        uniform sampler2D uSampler;

        void main(void) {
        vec4 textureColor = texture2D(uSampler, vec2(vTextureCoord.s, vTextureCoord.t));
        gl_FragColor = vec4(textureColor.rgb * vLightWeighting, textureColor.a);
        }
    </script>

    <script id="shader-vs" type="x-shader/x-vertex">
        attribute vec3 aVertexPosition;
        attribute vec3 aVertexNormal;
        attribute vec2 aTextureCoord;

        uniform mat4 uMVMatrix;
        uniform mat4 uPMatrix;
        uniform mat4 uNMatrix;

        uniform vec3 uAmbientColor;

        uniform vec3 uPointLightingLocation;
        uniform vec3 uPointLightingColor;

        uniform bool uUseLighting;

        varying vec2 vTextureCoord;
        varying vec3 vLightWeighting;

        void main(void) {
        vec4 mvPosition = uMVMatrix * vec4(aVertexPosition, 1.0);
        gl_Position = uPMatrix * mvPosition;
        vTextureCoord = aTextureCoord;

        if (!uUseLighting) {
        vLightWeighting = vec3(1.0, 1.0, 1.0);
        } else {
        vec3 lightDirection = normalize(uPointLightingLocation - mvPosition.xyz);

        vec3 transformedNormal = (uNMatrix * vec4(aVertexNormal,1.0)).xyz;
        float directionalLightWeighting = max(dot(transformedNormal, lightDirection), 0.0);
        vLightWeighting = uAmbientColor + uPointLightingColor * directionalLightWeighting;
        }
        }
    </script>


    <script type="text/javascript">

        var gl;

        function initGL(canvas) {
            try {
                gl = canvas.getContext("experimental-webgl");
                gl.viewportWidth = canvas.width;
                gl.viewportHeight = canvas.height;
            } catch (e) {
            }
            if (!gl) {
                alert("Could not initialise WebGL, sorry :-(");
            }
        }


        function getShader(gl, id) {
            var shaderScript = document.getElementById(id);
            if (!shaderScript) {
                return null;
            }

            var str = "";
            var k = shaderScript.firstChild;
            while (k) {
                if (k.nodeType == 3) {
                    str += k.textContent;
                }
                k = k.nextSibling;
            }

            var shader;
            if (shaderScript.type == "x-shader/x-fragment") {
                shader = gl.createShader(gl.FRAGMENT_SHADER);
            } else if (shaderScript.type == "x-shader/x-vertex") {
                shader = gl.createShader(gl.VERTEX_SHADER);
            } else {
                return null;
            }

            gl.shaderSource(shader, str);
            gl.compileShader(shader);

            if (!gl.getShaderParameter(shader, gl.COMPILE_STATUS)) {
                alert(gl.getShaderInfoLog(shader));
                return null;
            }

            return shader;
        }


        var shaderProgram;

        function initShaders() {
            var fragmentShader = getShader(gl, "shader-fs");
            var vertexShader = getShader(gl, "shader-vs");

            shaderProgram = gl.createProgram();
            gl.attachShader(shaderProgram, vertexShader);
            gl.attachShader(shaderProgram, fragmentShader);
            gl.linkProgram(shaderProgram);

            if (!gl.getProgramParameter(shaderProgram, gl.LINK_STATUS)) {
                alert("Could not initialise shaders");
            }

            gl.useProgram(shaderProgram);

            shaderProgram.vertexPositionAttribute = gl.getAttribLocation(shaderProgram, "aVertexPosition");
            gl.enableVertexAttribArray(shaderProgram.vertexPositionAttribute);

            shaderProgram.textureCoordAttribute = gl.getAttribLocation(shaderProgram, "aTextureCoord");
            gl.enableVertexAttribArray(shaderProgram.textureCoordAttribute);

            shaderProgram.vertexNormalAttribute = gl.getAttribLocation(shaderProgram, "aVertexNormal");
            gl.enableVertexAttribArray(shaderProgram.vertexNormalAttribute);

            shaderProgram.pMatrixUniform = gl.getUniformLocation(shaderProgram, "uPMatrix");
            shaderProgram.mvMatrixUniform = gl.getUniformLocation(shaderProgram, "uMVMatrix");
            shaderProgram.nMatrixUniform = gl.getUniformLocation(shaderProgram, "uNMatrix");
            shaderProgram.samplerUniform = gl.getUniformLocation(shaderProgram, "uSampler");
            shaderProgram.useLightingUniform = gl.getUniformLocation(shaderProgram, "uUseLighting");
            shaderProgram.ambientColorUniform = gl.getUniformLocation(shaderProgram, "uAmbientColor");
            shaderProgram.pointLightingLocationUniform = gl.getUniformLocation(shaderProgram, "uPointLightingLocation");
            shaderProgram.pointLightingColorUniform = gl.getUniformLocation(shaderProgram, "uPointLightingColor");
        }


        function handleLoadedTexture(texture) {
            gl.pixelStorei(gl.UNPACK_FLIP_Y_WEBGL, true);
            gl.bindTexture(gl.TEXTURE_2D, texture);
            gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, gl.RGBA, gl.UNSIGNED_BYTE, texture.image);
            gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.LINEAR);
            gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR_MIPMAP_NEAREST);
            gl.generateMipmap(gl.TEXTURE_2D);

            gl.bindTexture(gl.TEXTURE_2D, null);
        }


        var moonTexture;
        var crateTexture;

        function initTextures() {
            moonTexture = gl.createTexture();
            moonTexture.image = new Image();
            moonTexture.image.onload = function () {
                handleLoadedTexture(moonTexture)
            }
            moonTexture.image.src = "../texture/moon.gif";

            crateTexture = gl.createTexture();
            crateTexture.image = new Image();
            crateTexture.image.onload = function () {
                handleLoadedTexture(crateTexture)
            }
            crateTexture.image.src = "../texture/crate.gif";
        }


        var mvMatrix;
        var mvMatrixStack = [];
        var pMatrix;

        function mvPushMatrix() {
            var copy = new okMat4();
            mvMatrix.clone(copy);
            mvMatrixStack.push(copy);
        }

        function mvPopMatrix() {
            if (mvMatrixStack.length == 0) {
                throw "Invalid popMatrix!";
            }
            mvMatrix = mvMatrixStack.pop();
        }


        function setMatrixUniforms() {
            gl.uniformMatrix4fv(shaderProgram.pMatrixUniform, false, pMatrix.toArray());
            gl.uniformMatrix4fv(shaderProgram.mvMatrixUniform, false, mvMatrix.toArray());

            var normalMatrix = mvMatrix.inverse().transpose();
            gl.uniformMatrix4fv(shaderProgram.nMatrixUniform, false, normalMatrix.toArray());
        }








        function degToRad(degrees) {
            return degrees * Math.PI / 180;
        }


        var cubeVertexPositionBuffer;
        var cubeVertexNormalBuffer;
        var cubeVertexTextureCoordBuffer;
        var cubeVertexIndexBuffer;

        var moonVertexPositionBuffer;
        var moonVertexNormalBuffer;
        var moonVertexTextureCoordBuffer;
        var moonVertexIndexBuffer;

        function initBuffers() {
            cubeVertexPositionBuffer = gl.createBuffer();
            gl.bindBuffer(gl.ARRAY_BUFFER, cubeVertexPositionBuffer);
            vertices = [
                // Front face
                -1.0, -1.0, 1.0,
                 1.0, -1.0, 1.0,
                 1.0, 1.0, 1.0,
                -1.0, 1.0, 1.0,

                // Back face
                -1.0, -1.0, -1.0,
                -1.0, 1.0, -1.0,
                 1.0, 1.0, -1.0,
                 1.0, -1.0, -1.0,

                // Top face
                -1.0, 1.0, -1.0,
                -1.0, 1.0, 1.0,
                 1.0, 1.0, 1.0,
                 1.0, 1.0, -1.0,

                // Bottom face
                -1.0, -1.0, -1.0,
                 1.0, -1.0, -1.0,
                 1.0, -1.0, 1.0,
                -1.0, -1.0, 1.0,

                // Right face
                 1.0, -1.0, -1.0,
                 1.0, 1.0, -1.0,
                 1.0, 1.0, 1.0,
                 1.0, -1.0, 1.0,

                // Left face
                -1.0, -1.0, -1.0,
                -1.0, -1.0, 1.0,
                -1.0, 1.0, 1.0,
                -1.0, 1.0, -1.0
            ];
            gl.bufferData(gl.ARRAY_BUFFER, new Float32Array(vertices), gl.STATIC_DRAW);
            cubeVertexPositionBuffer.itemSize = 3;
            cubeVertexPositionBuffer.numItems = 24;

            cubeVertexNormalBuffer = gl.createBuffer();
            gl.bindBuffer(gl.ARRAY_BUFFER, cubeVertexNormalBuffer);
            var vertexNormals = [
                // Front face
                 0.0, 0.0, 1.0,
                 0.0, 0.0, 1.0,
                 0.0, 0.0, 1.0,
                 0.0, 0.0, 1.0,

                // Back face
                 0.0, 0.0, -1.0,
                 0.0, 0.0, -1.0,
                 0.0, 0.0, -1.0,
                 0.0, 0.0, -1.0,

                // Top face
                 0.0, 1.0, 0.0,
                 0.0, 1.0, 0.0,
                 0.0, 1.0, 0.0,
                 0.0, 1.0, 0.0,

                // Bottom face
                 0.0, -1.0, 0.0,
                 0.0, -1.0, 0.0,
                 0.0, -1.0, 0.0,
                 0.0, -1.0, 0.0,

                // Right face
                 1.0, 0.0, 0.0,
                 1.0, 0.0, 0.0,
                 1.0, 0.0, 0.0,
                 1.0, 0.0, 0.0,

                // Left face
                -1.0, 0.0, 0.0,
                -1.0, 0.0, 0.0,
                -1.0, 0.0, 0.0,
                -1.0, 0.0, 0.0,
            ];
            gl.bufferData(gl.ARRAY_BUFFER, new Float32Array(vertexNormals), gl.STATIC_DRAW);
            cubeVertexNormalBuffer.itemSize = 3;
            cubeVertexNormalBuffer.numItems = 24;

            cubeVertexTextureCoordBuffer = gl.createBuffer();
            gl.bindBuffer(gl.ARRAY_BUFFER, cubeVertexTextureCoordBuffer);
            var textureCoords = [
                // Front face
                0.0, 0.0,
                1.0, 0.0,
                1.0, 1.0,
                0.0, 1.0,

                // Back face
                1.0, 0.0,
                1.0, 1.0,
                0.0, 1.0,
                0.0, 0.0,

                // Top face
                0.0, 1.0,
                0.0, 0.0,
                1.0, 0.0,
                1.0, 1.0,

                // Bottom face
                1.0, 1.0,
                0.0, 1.0,
                0.0, 0.0,
                1.0, 0.0,

                // Right face
                1.0, 0.0,
                1.0, 1.0,
                0.0, 1.0,
                0.0, 0.0,

                // Left face
                0.0, 0.0,
                1.0, 0.0,
                1.0, 1.0,
                0.0, 1.0,
            ];
            gl.bufferData(gl.ARRAY_BUFFER, new Float32Array(textureCoords), gl.STATIC_DRAW);
            cubeVertexTextureCoordBuffer.itemSize = 2;
            cubeVertexTextureCoordBuffer.numItems = 24;

            cubeVertexIndexBuffer = gl.createBuffer();
            gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, cubeVertexIndexBuffer);
            var cubeVertexIndices = [
                0, 1, 2, 0, 2, 3,    // Front face
                4, 5, 6, 4, 6, 7,    // Back face
                8, 9, 10, 8, 10, 11,  // Top face
                12, 13, 14, 12, 14, 15, // Bottom face
                16, 17, 18, 16, 18, 19, // Right face
                20, 21, 22, 20, 22, 23  // Left face
            ];
            gl.bufferData(gl.ELEMENT_ARRAY_BUFFER, new Uint16Array(cubeVertexIndices), gl.STATIC_DRAW);
            cubeVertexIndexBuffer.itemSize = 1;
            cubeVertexIndexBuffer.numItems = 36;


            var latitudeBands = 30;
            var longitudeBands = 30;
            var radius = 2;

            var vertexPositionData = [];
            var normalData = [];
            var textureCoordData = [];
            for (var latNumber = 0; latNumber <= latitudeBands; latNumber++) {
                var theta = latNumber * Math.PI / latitudeBands;
                var sinTheta = Math.sin(theta);
                var cosTheta = Math.cos(theta);

                for (var longNumber = 0; longNumber <= longitudeBands; longNumber++) {
                    var phi = longNumber * 2 * Math.PI / longitudeBands;
                    var sinPhi = Math.sin(phi);
                    var cosPhi = Math.cos(phi);

                    var x = cosPhi * sinTheta;
                    var y = cosTheta;
                    var z = sinPhi * sinTheta;
                    var u = 1 - (longNumber / longitudeBands);
                    var v = 1 - (latNumber / latitudeBands);

                    normalData.push(x);
                    normalData.push(y);
                    normalData.push(z);
                    textureCoordData.push(u);
                    textureCoordData.push(v);
                    vertexPositionData.push(radius * x);
                    vertexPositionData.push(radius * y);
                    vertexPositionData.push(radius * z);
                }
            }

            var indexData = [];
            for (var latNumber = 0; latNumber < latitudeBands; latNumber++) {
                for (var longNumber = 0; longNumber < longitudeBands; longNumber++) {
                    var first = (latNumber * (longitudeBands + 1)) + longNumber;
                    var second = first + longitudeBands + 1;
                    indexData.push(first);
                    indexData.push(second);
                    indexData.push(first + 1);

                    indexData.push(second);
                    indexData.push(second + 1);
                    indexData.push(first + 1);
                }
            }

            moonVertexNormalBuffer = gl.createBuffer();
            gl.bindBuffer(gl.ARRAY_BUFFER, moonVertexNormalBuffer);
            gl.bufferData(gl.ARRAY_BUFFER, new Float32Array(normalData), gl.STATIC_DRAW);
            moonVertexNormalBuffer.itemSize = 3;
            moonVertexNormalBuffer.numItems = normalData.length / 3;

            moonVertexTextureCoordBuffer = gl.createBuffer();
            gl.bindBuffer(gl.ARRAY_BUFFER, moonVertexTextureCoordBuffer);
            gl.bufferData(gl.ARRAY_BUFFER, new Float32Array(textureCoordData), gl.STATIC_DRAW);
            moonVertexTextureCoordBuffer.itemSize = 2;
            moonVertexTextureCoordBuffer.numItems = textureCoordData.length / 2;

            moonVertexPositionBuffer = gl.createBuffer();
            gl.bindBuffer(gl.ARRAY_BUFFER, moonVertexPositionBuffer);
            gl.bufferData(gl.ARRAY_BUFFER, new Float32Array(vertexPositionData), gl.STATIC_DRAW);
            moonVertexPositionBuffer.itemSize = 3;
            moonVertexPositionBuffer.numItems = vertexPositionData.length / 3;

            moonVertexIndexBuffer = gl.createBuffer();
            gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, moonVertexIndexBuffer);
            gl.bufferData(gl.ELEMENT_ARRAY_BUFFER, new Uint16Array(indexData), gl.STREAM_DRAW);
            moonVertexIndexBuffer.itemSize = 1;
            moonVertexIndexBuffer.numItems = indexData.length;
        }


        var moonAngle = 180;
        var cubeAngle = 0;

        function drawScene() {
            gl.viewport(0, 0, gl.viewportWidth, gl.viewportHeight);
            gl.clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT);

            pMatrix = okMat4Proj(45, gl.viewportWidth / gl.viewportHeight, 0.1, 100.0);

            var lighting = document.getElementById("lighting").checked;
            gl.uniform1i(shaderProgram.useLightingUniform, lighting);
            if (lighting) {
                gl.uniform3f(
                    shaderProgram.ambientColorUniform,
                    parseFloat(document.getElementById("ambientR").value),
                    parseFloat(document.getElementById("ambientG").value),
                    parseFloat(document.getElementById("ambientB").value)
                );

                gl.uniform3f(
                    shaderProgram.pointLightingLocationUniform,
                    parseFloat(document.getElementById("lightPositionX").value),
                    parseFloat(document.getElementById("lightPositionY").value),
                    parseFloat(document.getElementById("lightPositionZ").value)
                );

                gl.uniform3f(
                    shaderProgram.pointLightingColorUniform,
                    parseFloat(document.getElementById("pointR").value),
                    parseFloat(document.getElementById("pointG").value),
                    parseFloat(document.getElementById("pointB").value)
                );
            }

            mvMatrix = okMat4Trans(0.0, 0.0, -20.0);

            mvPushMatrix();
            mvMatrix.rotY(OAK.SPACE_LOCAL, moonAngle, true);
            mvMatrix.translate(OAK.SPACE_LOCAL, 5, 0, 0, true);
            gl.activeTexture(gl.TEXTURE0);
            gl.bindTexture(gl.TEXTURE_2D, moonTexture);
            gl.uniform1i(shaderProgram.samplerUniform, 0);

            gl.bindBuffer(gl.ARRAY_BUFFER, moonVertexPositionBuffer);
            gl.vertexAttribPointer(shaderProgram.vertexPositionAttribute, moonVertexPositionBuffer.itemSize, gl.FLOAT, false, 0, 0);

            gl.bindBuffer(gl.ARRAY_BUFFER, moonVertexTextureCoordBuffer);
            gl.vertexAttribPointer(shaderProgram.textureCoordAttribute, moonVertexTextureCoordBuffer.itemSize, gl.FLOAT, false, 0, 0);

            gl.bindBuffer(gl.ARRAY_BUFFER, moonVertexNormalBuffer);
            gl.vertexAttribPointer(shaderProgram.vertexNormalAttribute, moonVertexNormalBuffer.itemSize, gl.FLOAT, false, 0, 0);

            gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, moonVertexIndexBuffer);
            setMatrixUniforms();
            gl.drawElements(gl.TRIANGLES, moonVertexIndexBuffer.numItems, gl.UNSIGNED_SHORT, 0);
            mvPopMatrix();

            mvPushMatrix();
            mvMatrix.rotY(OAK.SPACE_LOCAL, cubeAngle, true);
            mvMatrix.translate(OAK.SPACE_LOCAL, 5, 0, 0, true);
            gl.bindBuffer(gl.ARRAY_BUFFER, cubeVertexPositionBuffer);
            gl.vertexAttribPointer(shaderProgram.vertexPositionAttribute, cubeVertexPositionBuffer.itemSize, gl.FLOAT, false, 0, 0);

            gl.bindBuffer(gl.ARRAY_BUFFER, cubeVertexNormalBuffer);
            gl.vertexAttribPointer(shaderProgram.vertexNormalAttribute, cubeVertexNormalBuffer.itemSize, gl.FLOAT, false, 0, 0);

            gl.bindBuffer(gl.ARRAY_BUFFER, cubeVertexTextureCoordBuffer);
            gl.vertexAttribPointer(shaderProgram.textureCoordAttribute, cubeVertexTextureCoordBuffer.itemSize, gl.FLOAT, false, 0, 0);

            gl.activeTexture(gl.TEXTURE0);
            gl.bindTexture(gl.TEXTURE_2D, crateTexture);
            gl.uniform1i(shaderProgram.samplerUniform, 0);

            gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, cubeVertexIndexBuffer);
            setMatrixUniforms();
            gl.drawElements(gl.TRIANGLES, cubeVertexIndexBuffer.numItems, gl.UNSIGNED_SHORT, 0);
            mvPopMatrix();
        }


        var lastTime = 0;

        function animate() {
            var timeNow = new Date().getTime();
            if (lastTime != 0) {
                var elapsed = timeNow - lastTime;

                moonAngle += 0.05 * elapsed;
                cubeAngle += 0.05 * elapsed;
            }
            lastTime = timeNow;
        }



        function tick() {
            okRequestAnimationFrame(tick);
            drawScene();
            animate();
        }


        function webGLStart() {
            var canvas = document.getElementById("lesson12-canvas");
            initGL(canvas);
            initShaders();
            initBuffers();
            initTextures();

            gl.clearColor(0.0, 0.0, 0.0, 1.0);
            gl.enable(gl.DEPTH_TEST);

            tick();
        }

    </script>


</head>


<body onload="webGLStart();">
    <canvas id="lesson12-canvas" style="border: none;" width="500" height="500"></canvas>
    <br />

    <input type="checkbox" id="lighting" checked />开启光照<br />
    <br />

    <h2>点光源：</h2>

    <table style="border: 0; padding: 10px;">
        <tr>
            <td><b>位置：</b>
            <td>X: <input type="text" id="lightPositionX" value="0.0" />
            <td>Y: <input type="text" id="lightPositionY" value="0.0" />
            <td>Z: <input type="text" id="lightPositionZ" value="-20.0" />
        </tr>
        <tr>
            <td><b>颜色：</b>
            <td>R: <input type="text" id="pointR" value="0.8" />
            <td>G: <input type="text" id="pointG" value="0.8" />
            <td>B: <input type="text" id="pointB" value="0.8" />
        </tr>
    </table>

    <h2>环境光：</h2>

    <table style="border: 0; padding: 10px;">
        <tr>
            <td><b>颜色</b>
            <td>R: <input type="text" id="ambientR" value="0.2" />
            <td>G: <input type="text" id="ambientG" value="0.2" />
            <td>B: <input type="text" id="ambientB" value="0.2" />
        </tr>
    </table>
    <br />
</body>

</html>